Process and apparatus for classifying materials



April 5, 1949. A. D. SINDEN 2,466,491

PROCESS AND APPARATUS FOR CLASSIFYING MATERIALS Filed Sept. 10, 1943 4Sheets-Sheet l FIE].

INVENTOR.

April 5, 1949. A. D. SINDEN 2,466,491

PROCESS AND APPARATUS FOR CLASSIFYING' MATERIALS Filed Sept. 10, 1943 4Sheets-Sheet 2 I INVENTOR.

l aLfr'd I]n fiz'ndan April 5, 1949.

PROCESS AND Filed Sept. 10, 1943 Dz'scharzgns m INVENTOR. dlfr'ed D. 61nden.

' Filed Sept. 10, 1945 4 Sheets-Sheet 4 April 5, 1949. A. D. SINDEN2,466,491

PROCESS AND APPARATUS FOR CLASSIFYING MATERIALS INVENTOR.

dlfr'ed D. Sjndan. BY

Patented Apr. 5, 1949 UNITED STATES PATENT OFFICE PROCESS AND APPARATUSFOR CLASSIFYING MATERIALS 11 Claims.

The principal object of this invention is to provide a commerciallypractical process and apparatus for accurately and rapidly classifyingmaterials between 10 mesh and 100 mesh. So far as I know, no process orapparatus having the emciency of that provided by the present inventionis now available.

Generally speaking, this principal object is accomplished by forming thematerial to be separated into a flat stream of suitable speed andintersecting that stream with a flat jet or current of air. The mostsatisfactory results with ground limestone have been had with apparatusin which the stream of material to be separated is directed downwardlyat approximately 45 degrees, and the intersecting stream of air isdirected downwardly at right angles to the first stream, and thereforeat 45 degrees also.

In this most satisfactory apparatus yet developed, the stream ofmaterial is formed by an endless belt travelling about idlers, one ofwhich is driven, and within the group of which the belt is looped abouta drum formed of spaced rings and enclosing a screw conveyor, the casingof which is slotted to provide feed openings to direct the material ontothe belt in such a posi--- tion that it will gather sufficient speed topass around the loop and be delivered from the upper side thereof in astream directed downwardly at 45 degrees.

The thickness of the stream, its speed, the relative speed of the streamof material and the stream of air or other fluid will, of course. bevaried to correspond with the conditions imposed by the particularmaterial to be separated.

In the accompanying drawings illustrating the best known form of theapparatus- Fig. 1 is a side elevation with practically all of themechanism enclosed within a casing;

Fig. 2 is a vertical section taken on the line 2 -'2 of Fig. 1;

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 2;

Fig. 4 is a section taken on the broken line 4-4 of Fig. 1; and

Fig. 5 is a detail of the conveyor casing and the means for varying thesize of the feed openings and the height of the feeding edge above thebottom of the conveyor casing.

But these drawings and the corresponding description are used for thepurpose of disclosure only and are not intended to impose anylimitations on the claims beyond what is made necessary by the priorart.

In these drawings and with particular reference now to Figs. 1 and 3,the means for project ing a mixture of different sizes of material in astream is shown generally at A, the blower at B, the dust separator atC, and the discharge chutes for the classified material at D, all ofthese being within a casing generally indicated atE and supported upon asuitable framework generally indicated at F.

The projecting means A includes an endless belt 18 running on fouridlers ll, l2, l3, and I4 grouped around a drum l5, and about which thebelt is looped substantially as shown in Fig.

As best shown in Fig. 2, the drum is made up of a series of spaced ringsHi secured in proper relation by rods IT, to which they are welded orotherwise made fast. The right end ring [8 in Fig. 2 has a reduced hubportion l9 fitted with a hardened ring 9 to run against idlers 20journalled on anti-friction bearings generally indicated at El. With thearrangement of the belt shown and the location of the idlers 20 shown inFig. 1, two are necessary, though three or more may be used ifpreferred.

The left ring 22 of the drum has an extended hub 23 journalled onanti-friction bearings 24 carried at the outside of the casing E as bestshown in Fig. 2. This is the driven end of the drum, and the arrangementof bearings gives it a satisfactory support, although, of course, somewill prefer to use the same sort of mounting as is shown for the rightend of the drum.

The end rings l8 and 22 have peripheral flanges 26 which, together withthe circumferences of the intermediate rings, form the drum surface onwhich the belt [0 runs.

In this particular apparatus, the material to be classified is chargedat 21 (Fig. 2) into a cylindrical casing 28 for a screw conveyor 29. Forconvenience in drive, the screw 29 is made coaxial with the drum l5, andits shaft 30 projects through a tubular extension 3i on the casing toconnect with the drive generally indicated at G (Fig. 2).

The conveyor casing is provided with a series of openings or slots 32,here shown as rectangular and located in alignment with the spacesbetween adjacent rings of the drum. The size of those slots and theposition of the lower edge will be varied to suit the material and otheroperating conditions. The pitch of the screw will determine how high thematerial tends to ride up on the conveyor casing, and the lower edge ofthe slots probably will have to be adjusted to suit the difierentmaterials; but, generally speaking, that edge should be somewhere around20 to 30 degrees from the bottom meridian of the conveyor casing. In theapparatus here shown, the casing is provided with a strip or bar 33(Fig. having its ends adjustably mounted in guides 34 and made fast bypins 35, so that the operator can by cut and try get the most suitableadjustment for the material. The conveyor will probably keep thematerial above the slots and the adjustment of the strip will determinethe speed with which the material is fed from the conveyor casing ontothe belt.

It will be observed from Fig. 3 that the material will be fed onto thebelt in the general area indicated by the arrow H as it is proceedingdownwardly and to the left. This will afford suflicient opportunity forthe material to get the necessary speed and travel by centrifugal forceon the belt around to the approximate position of the idler II, fromwhich position it will be projected in a stream indicated by the arrow36 passing through a tube or passageway 31 by which it is conductedbeyond the idler l2 at the lower right corner of the group of idlers ll,[2, l3, and [4.

As before indicated, the thickness of the stream and its speed will bevaried to suit the particular materials and other operating conditions.

In this particular apparatus, which has been found satisfactory forground limestone, the fluid for the intersecting stream is air and issupplied by a centrifugal blower B, delivering through an air passage 38in the general direction indicated by the arrow 39 intersecting thestream of material at right angles and within a sizable separatingchamber generally indicated by 40. The thickness and the speed of theair stream will be a matter of choice and design to meet particularconditions and personal preference. Its effect is to take hold of theparticles or lumps of material in the stream 36 and deflect them fromthe indicated course to an extent that is determined by their mass,volume, and shape, all of which affect the resistance they offer to theair stream, but the net result is that the material is separatedapproximately according to size, the heavier particles being deflectedthe least, the next heavier the next least, and so on until theimpalpable powder is reached, which is entrained by the air stream andpasses into the dust separator C.

In this particular apparatus, the separating chamber 40 is provided withadjustable vanes 4| and 42 (Fig. 3), which may be set from the outsideof the casing by the levers 43 and 44 and locked in position by the wingnuts 45 and 46. These vanes effect a separation of the classifiedmaterial between three passages 41, 48, and 49,

ending in chutes 50, 5|, and 52. These, of course, are merelyillustrative. Any number of chutes and passages may be used.

The impalpable powder or dust entering the separator through the curvedpassage 53 will, in the main, be discharged at slot 54 and settled downinto the discharge 12. Any remainder that is not so removed by the firstpassage in the separator will be fed in through the slit 55 to the mainstream from the oncoming current of air.

The ends of the separator C are connected with return conduits 56leading back to the end inlets 51 of the blower B. This arrangement ofstreams at 45 degrees with respect to the vertical and right angles toeach other provides surfaces generally too steep for the angles ofrepose of any of the materials to be handled, and particularly the veryfine material. In order to prevent dust from gathering just above theintersection of the two streams in the area indicated by 58, a slot 59is provided to effect a continual feed into the swiftly moving stream,which will result as, of course, from Bernoullis theory.

As the streams intersect, there is a farming out of the material streamand, of course, some deflection of the air stream, but, in the main,there i a considerable part of the air stream continu ing generally inthe line of the arrow 39. The circular portion of the dust separator iscut off from the separating chamber 40 by the angular plates 62, at thecorner of which is the adjustable blade 63 which serves to shear thecurrents as the air and impalpable powder form the stream passing intothe separator.

The entire apparatus is driven from a single electric motor 64 throughthe drive designated G in Fig. 2, comprising V belts $5 running overgrooved pulleys 66 on the blower shaft and 61 on the shaft for the idlerI l, as shown in Fig. 3. The motor is mounted on the top 68 of thecasing E by hinges 69 at the left in Fig. 3 and adjustable bolts 10 atthe right, whereby the belt tension can be regulated to suit conditions.

In this apparatus especially designed for classifying ground limestoneat 10 mesh, 20 mesh, 40 mesh, and mesh, the belt is 24 inches wide witha lineal speed of 1600 F. P..M., While the air velocity in the jet orstream indicated by the arrow 39 is 5,000 F. P. M. The apparatus willsatisfactorily handle a speed of 15 tons per hour. It is contemplatedthat apparatus will be designed with belts as wide as 48 inches, if notwider, and, as before indicated, the characteristics of differentmaterials will require corresponding variations in the size and speed ofthe apparatus forming the two streams.

Enclosing the entire apparatus within the tight casing E and thearrangements for collecting all the dust and delivering it to anappropriate discharge is of great advantage in this apparatus.

I claim:

1. The process of classifying which includes forcibly projecting at aconstant speed all the particles of a mixture of different sizes ofmaterial in a relatively thin stream of uniform thickness that isinclined downwardly so as to have a substantial vertical component andintersecting the stream of material substantially right angularly with adownwardly inclined fluid stream to deflect particles of the materialaccording to their resistance to the fluid stream, whereby gravity andthe projecting force are additive in opposition to the deflectingtendency of the fluid stream and the difference in deflection of lightand heavy particles is enhanced.

2. The process of classifying which includes conveying a mixture ofdifferent sizes of material substantially horizontally, forming theconveyed material into a whirl about a substantially horizontal axis,discharging the material tangentially from the whirl in a downwardlyinclined fast stream, of considerable width and of uniform thicknessalong its length and intersecting the fast stream of material with afluid stream directed downwardly and inclined oppositely to the streamof material to deflect the material according to the resistance to thefluid stream.

3. In apparatus of the class described, means for projecting a mixtureof different sizes of material in a downwardly inclined stream includinga hollow, radially open drum mounted for rotation on a substantiallyhorizontal axis, a belt running in a loop about said drumand a conveyorfor conveying material into the drum and distributing evenly across thebelt, and means for intersecting the stream of material projected by thebelt with a downwardly directed and oppositely inclined stream of fluidto deflect the material according to the resistance to the fluid stream.

4. In apparatus of the class described, means for projecting a mixtureof different sizes of material in a stream including an open, hollowdrum comprising axially spaced rings journalled on a substantiallyhorizontal axis and unconnected to each other at their peripheries, aconveyor running lengthwise to and inside of the drum feeding materialthrough openings in the drum to its periphery, a belt looped about saidperiphery for receiving said material in a substantially even layeracross the belt, and means for intersecting the stream of materialprojected by the belt with a stream of fluid to deflect particles of thematerial according to their resistance to the fluid stream.

5. In apparatus of the class described, means for projecting a mixtureof different sizes of material in a flat, wide stream of uniformthickness, said means including a hollow, radially open drum, a beltrunnin on idlers grouped around said drum, said drum Comprising axiallyspaced rings unconnected to each other at their peripheries, and meansfor intersecting the stream of material projected by the belt with astream of fluid to deflect particles of the material according to theirresistance to the fluid stream.

6. In apparatus of the class described, means for projecting a mixtureof difierent sizes of material in a flat, wide stream including ahollow, radially open drum mounted for rotation on a substantiallyhorizontal axis, a belt running in a loop about said drum, a screwconveyor running into the drum including a casing open at one side tofeed material in an even layer on the belt, means for intersecting thestream of material projected by the belt with a stream of fluid todeflect particles of the material according to their resistance to thefluid stream, and means for varyin the effective opening in the side ofthe conveyor casing.

7. In apparatus of the class described, means for projecting a mixtureof different sizes of material in a flat, wide stream of uniformthickness, said means including a radially open hollow drum of spacedrings unconnected at their peripheries, a wide belt loop about the drumand a conveyor runnin into'the drum for feeding material between therings to the belt, and means for intersecting the stream of materialprojected by the belt with a stream of fluid to deflect particles of thematerial according to their resistance to the fluid stream.

8. In apparatus of the class described, an enclosure providing apassageway, means for projecting through the passageway all theparticles of a mass of mixed sizes in a wide, thin stream ofsubstantially uniform thickness lengthwise of the stream at high anduniform velocity with all the particles moving in substantially the samedirection, said means comprising a plurality of axially spaced ringsforming an open drum, a belt driven around the drum in contact with therings and means feeding mixed particles through the drum to the belt, incombination with means for directing a stream of fluid into intersectingrelation with the particle stream to deflect particles according totheir resistance to the fluid stream.

9. In apparatus of the class described, an enclosure providing apassageway, means for projecting through the passageway all theparticles of a mass of mixed sizes in a wide, thin stream ofsubstantially uniform thickness lengthwise of the stream at high anduniform velocity with all the particles moving in substantially the samedirection said means comprising a plurality of axially spaced ringsforming an open drum, a belt driven around the drum in contact with therings and a conveyor extending lengthwise in the drum for supplyingmixed particles through the drum to the belt, in combination with meansfor directing a stream of fluid into intersecting relation with theparticle stream to deflect particles according to their resistance tothe fluid stream.

10. In apparatus of the class described, an enclosure providing a,passageway, means for projecting through the passageway all theparticles of a mass of mixed sizes in a wide, thin stream ofsubstantially uniform thickness lengthwise of the stream at high anduniform velocity with all the particles moving in the same direction,said means comprising a radially open hollow drum, a belt looped aroundthe drum in contact with it, means extending into the drum fordepositing particles on the belt in a layer of uniform thicknesslengthwise of the belt, means for driving the belt to project saidstream, and means for directing a stream of fluid into intersectingrelation with the particle stream to deflect particles according totheir resistance to the fluid stream.

11. The process of classifying which includes projecting all theparticles of a mass of mixed sizes through a passageway in the form of awide, thin stream of substantially uniform thickness lengthwise of thestream at high and uniform velocity with all the particles moving insubstantially the same direction and spaced from the walls of thepassageway by a layer of air moving with the stream, and intersectingthe stream with a stream of fluid to deflect particles according totheir resistance to the fluid stream.

ALFRED D. SINDEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,080 Phillips et al May 4, 1841530,445 Newby Dec. 4, 1894 974,395 Kidder Nov. 1, 1910 1,066,918 KidderJuly 8, 1913 1,346,015 Gibson July 6, 1920 1,348,043 Parkinson July 27,1920 1,420,593 Titchmarsh June 20, 1922 1,491,429 Stebbins Apr. 22, 19241,903,046 Hunter Mar. 28, 1933 2,081,182 Malke May 25, 1937 2,135,716Johnson Nov. 8, 1938 2,210,505 Sinden Aug. 6., 1940 2,247,385 HuyettJuly 1, 1941 FOREIGN PATENTS Number Country Date 589,236 France Feb. 18,1935 828,125 France Feb. 7, 1938 Certificate of Correction Patent No.2,466,491. April 5, 1949.

ALFRED D. SIN DEN It is hereby certified that errors appear in theprinted specification of the above numbered patent requiring correctionas follows:

Column 4, line 43, claim 1, before the word constant strike out a;column 5, line 52, claim 7, for loop read looped;

and that the said Letters Patent should beread with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 6th day of September, A. D. 1949.

THOMAS F. MURPHY,

Am'atant Uommksioner of Patents.

